As 3D display technologies have become part of a next wave of promising technologies for consumer electronics, a demand for 3D content is rapidly increasing. The conversion of image data from 2D to 3D, a fast way to obtain 3D content from existing 2D content, has been extensively studied. Nevertheless, most of the existing 2D-to-3D conversion technologies are for videos or a sequence of images, but not for a single image. The conversion of a single image from 2D to 3D is a challenging problem due at least in part to the fact that the single 2D image data lacks depth information, motion information, and prior knowledge about the scene or objects to be reconstructed in a 3D format.
Although some technologies have been developed for single image 2D to 3D conversion, most of those technologies focus on conversion of outdoor or indoor images taken at a moderate or far distance (e.g., over 10 meters from a camera). In addition, most conventional technologies reconstruct a 3D scene or object under a general setting for the scene or object and are based on segmentation and learning techniques. However, these technologies do not work well for converting a single close-up or portrait image into a 3D image.